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Home Energy Audit Calculator

Last updated: April 2026

Property details

Current home features

Loft and roof

Walls

Windows

Heating

Potential saving

£1,965/year

Current bill

£1,800

After improvements

£0

Saving

109.2%

Recommended improvements

ImprovementSaving/yrCostPaybackPriority
Loft insulationNo loft insulation£330£4001.2yrHigh
Draught proofingNot fully draught proofed£80£1201.5yrHigh
Cavity wall insulationCavity walls not insulated£300£5001.7yrHigh
Smart thermostatNo smart thermostat£110£2001.8yrHigh
LED lightingNot fitted throughout£70£1502.1yrHigh
New A-rated boilerOld D-G rated boiler£840£2,5003yrHigh
Double glazingSingle glazed windows£235£4,00017yrLow
Total£1,965£7,8704yr

Government funding available

  • Great British Insulation Scheme
  • Boiler Upgrade Scheme

Check eligibility at gov.uk before commissioning work.

Quick wins

  • Loft insulation: £330/year, payback 1.2yr
  • Draught proofing: £80/year, payback 1.5yr
  • Cavity wall insulation: £300/year, payback 1.7yr
  • Smart thermostat: £110/year, payback 1.8yr

EPC note

These improvements could raise your EPC rating from approximately E to C. A higher EPC rating can improve comfort, reduce running costs, and support property value.

What is a home energy audit?

A home energy audit identifies where your home is losing heat and energy, then estimates the potential savings from improvements. This calculator uses typical UK savings data for different property types.

What are the biggest energy saving improvements?

The most cost-effective improvements for many UK homes are loft insulation, cavity wall insulation, replacing an old boiler, fitting heating controls, switching to LEDs, and draught proofing.

What government schemes are available for home insulation?

The Great British Insulation Scheme can support loft and cavity wall insulation for eligible homes. ECO4 can fund larger measures for eligible households, and the Boiler Upgrade Scheme provides a grant toward an air source heat pump.

What does this mean?

This calculator is designed to help you understand the likely number before you make a decision or start an application.

Your result should be checked against official UK guidance, especially if your circumstances include dependants, exemptions, prior leave, or a complex immigration history.

Treat the figure as a planning tool rather than legal advice. Where the answer affects an application deadline or major payment, speak to an authorised adviser.

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